Deletion of genes encoding PU.1 and Spi-B in B cells impairs differentiation and induces pre-B cell acute lymphoblastic leukemia

Authors

Kristen M. Sokalski, Schulich School of Medicine & Dentistry
Stephen K.H. Li, Schulich School of Medicine & Dentistry
Ian Welch, Western University
Heather Anne T. Cadieux-Pitre, Western University
Marek R. Gruca, Schulich School of Medicine & Dentistry
Rodney P. DeKoter, Schulich School of Medicine & DentistryFollow

Document Type

Article

Publication Date

9-8-2011

Journal

Blood

Volume

118

Issue

10

First Page

2801

Last Page

2808

URL with Digital Object Identifier

10.1182/blood-2011-02-335539

Abstract

The E26 transformation-specific (Ets) transcription factor PU.1 is required to generate lymphoid progenitor cells from hematopoietic stem cells, but it is not required to generate B cells from committed B-cell lineage progenitors.We hypothesized that PU.1 function in B-cell differentiation is complemented by the related Ets transcription factor Spi-B. To test this hypothesis, mice were generated lacking both PU.1 and Spi-B in the B-cell lineage. Unlike mice lacking PU.1 or Spi-B, mice deficient in both PU.1 and Spi-B in the B-cell lineage had reduced frequencies of B cells as well as impaired B-cell differentiation. Strikingly, all PU.1 and Spi-B-deficient mice developed pre-B cell acute lymphoblastic leukemia before 30 weeks of age. Pre-B cells accumulated in the thymus resulting in massive thymic enlargement and dyspnea. These findings demonstrate that PU.1 and Spi-B are essential transcriptional regulators of B-cell differentiation as well as novel tumor suppressors in the B-cell lineage. © 2011 by The American Society of Hematology.